1. Field of the Invention
This invention relates to solving problems encountered in supporting, an instrument or other type of accessory, in various stable positions. It primarily resulted in the specific need of supporting, an instrument pre-amplifier, in close proximity to a patient undergoing a medical examination. A case where the need for the connecting leads between patient and the input to the pre-amplifier be as short as possible.
2. Description of Prior Art
This mechanism is unlike the ubiquitous support devices usually found in such items as desk lamps. The usual mechanisms depend on the approximating counter-balancing force of springs and pivotal friction. Since the stability of position is dependent on these forces, they are only truly balanced for non-variable and mostly static forces. When these ubiquitous support devices are used for applications other than lamp supports, their repeated positioning induces wear on the pivots destroying the integrity of the original friction forces plus any variable loading make these devices not conveniently effective to accomplish their intended purpose.
The mechanism described in this invention overcomes the above deficiencies since it is not dependent on spring forces to balance the forces of gravity. It becomes a constrained, fixed linkage, when subjected to the gravitational load of the supported object or appliance. It is useful as a support over a much wider range of weights than those of dedicated spring counter-balanced devices. Thus there is no gravitational drifting of position to cause annoyance and agrivation to its user.
Unlike the ubiquitous spring balanced parallelogram device described as prior art, this mechanism is a linkage to provide support and variable positioning to a physical item of interest and to maintain its selected position without any drifting from this position due to gravitational forces resulting from the weight of the supported object or mechanism. It is especially useful in applications where repeated specific position changes are required during an on going procedure. An example would be; such as supporting an input device during a physical examination of a prone or supine patient, especially when the input device must be located near various and changing examination sites.
It should be noted that a release lever is located adjacent to the appliance in use, thus facilitating easy access for its operation, a definite advantage, since this is always in the convenient proximity of the operator.